Japanese Patent Application Publication No. 2010-257898, Peter Hommelhoff, Yvan Sortais, Anoush Aghajani-Talesh, and Mark A. Kasevich, Physical Review Letters 96, 077401 (2006), and Anna Mustonen, Paul Beaud, Eugenie Kirk, Thomas Fetzer, and Soichiro Tsujino, Scientific Reports 2, p. 915 (2012) disclose photoinductive electron emission devices. These electron emission devices are each provided with an electron emission source and a laser beam irradiator. The electron emission source is provided with an acute conical metal. In such electron emission devices, when laser beam is irradiated from the laser beam irradiator to a tip of the conical metal, an optical electric field is applied to the tip of the conical metal, and electrons are emitted from the tip of the conical metal due to its tunneling effect.